Quest for the little pink pill
THE little blue pill known as Viagra is keeping many men in pleasure, and for a while there was hope that it would do the same for women. But now researchers know that women need something different to improve their desire for sex, and their enjoyment of it.
“A number of compounds effective in men have limited utility in women,” says Dr. Taylor Segraves, a psychiatrist at Case Western School of Medicine in Cleveland. Viagra and its cousins, Levitra and Cialis, increase blood flow to the genitals but often leave women feeling aroused but unsatisfied, experts note.
So attention is turning elsewhere. Several clinical studies are examining the ability of compounds to improve sexual problems in women -- be they low sex drive, slow response to physical stimulation or the inability to experience orgasm. Among the candidates: an anti-depressant, an herbal remedy and a precursor to sex hormones.
Studying women’s sex drive is not as straightforward as studying that of men, scientists say. With males, there are clear measures of what constitutes sexual function -- namely, the ability to sustain an erection.
And sometimes, in women, the order of events in a sexual encounter flip-flops compared with men, says clinical pharmacologist Dr. David Ferguson, of Clinical Research Services Consulting in Grand Marais, Minn. Desire, for example, which in men tends to start the fun, might come after stimulation, especially in a long-term relationship, Ferguson says.
Another reason for the complexity of sex research in general is that “so many things can influence libido,” Segraves says. Stress, lack of exercise and diet can all diminish one’s sex drive, as can rocky relationships -- or no relationships. Most studies require participants to be with committed partners to reduce these complications. They also require women to have sex once or twice a week to ensure enough data are collected.
Despite the difficulties, trials with pre-menopausal and post-menopausal women recruited from medical centers across the country are underway.
* Wellbutrin. Antidepressants are notorious for knocking down women’s libido, but one such drug seems to have a positive effect.
In a 2001 study published in the Journal of Sex and Marital Therapy, Segraves and colleagues found that bupropion, also known by the trade names Wellbutrin and Zyban, doubled how often 51 nondepressed women became interested in sex, became aroused and had fantasies. (Women took the drug for eight weeks and the researchers assessed their sexual functioning in interviews.)
“In most women the effect was only moderate -- but enough for the women to want to continue taking the drug,” Segraves says.
Another pilot study by Segraves found that the drug improves the number of times pre-menopausal women achieve orgasm. Now he and his colleagues are testing bupropion in 80 women with female orgasmic disorder, assessing not only improvements in their ability to experience orgasm but also changes in desire, arousal and pleasure.
Bupropion’s pro-sex effect might be due to how the drug works. Whereas antidepressants such as Prozac that are known to dampen the sex drive keep the brain exposed to heightened levels of the neurotransmitter serotonin, bupropion ups the brain levels of two different neurotransmitters, dopamine and norepinephrine.
* Zestra. This combination of botanical oils and extracts (principally borage seed oil, evening primrose oil, angelica extract, coleus extract and a couple of antioxidants as preservatives) is available in drugstores. Because it falls under the Food and Drug Administration’s cosmetic regulations, it is not subject to the same stringent rules as medical drugs.
In a 2003 study published in the Journal of Sex and Marital Therapy, the formula helped the majority of 20 women improve their levels of arousal and desire, even in the half of the group that didn’t have problems with desire.
“The results were astonishing,” Ferguson says of the bubblegum-scented massage oil, which is applied to the genitals. He noted, however, that for some women the oil could overstimulate.
Ferguson has now been hired by the makers of Zestra to investigate its effectiveness in a 200-woman clinical trial similar in design to ones drug companies would normally undertake. The women will use either Zestra or a placebo, keep a diary and be evaluated by researchers. Neither the doctors nor the patients will know who’s getting what until the end of the four-month study.
* DHEA. This hormone precursor is available without a prescription and is touted as a remedy for weight gain, hair loss and low libido. What’s lacking is scientific evidence on its effectiveness.
In the body, DHEA is converted into the female sex hormone estrogen and the male sex hormone testosterone, and as with all hormones, people make less of it as they get older. Now endocrinologist Dr. Susan Davis, of Monash University in Victoria, Australia, is recruiting 240 post-menopausal women with low libidos to take part in a study in which they will be given DHEA daily for a year.
Subjects will fill out questionnaires on sexual function, but researchers will also monitor their cholesterol levels, liver function and uterine linings to determine whether the compound is safe.
Answers to these trials are expected within a year or two, but some people aren’t waiting. Experts say that Wellbutrin is already being prescribed off-label for women (as is the male sex hormone testosterone, which doctors know can boost sex drive in both genders).
Meanwhile, Zestra and DHEA can be purchased without a doctor’s prescription, and experts believe women are already experimenting with them in the privacy of their homes.
As research in this area progresses, some physicians worry that people are seeking a pharmacological solution to something that should be dealt with in a different manner.
Dr. Erika Schwartz, of the Integrative Medicine Consultative Practice in New York City, says she’s concerned that people will start to rely on such remedies rather than trying to fix the underlying root of sexual problems. “I encourage people to not take anything indefinitely,” she says.
And one thing all these researchers agree upon: Women have a “low sex drive” only if they’re unsatisfied. And there is tremendous variability. Although about a fifth of women experience what physicians call hypoactive sexual desire disorder, no absolute frequency exists below which researchers consider a person’s sex drive low.
“For one person, having sex 25 times a month and having that drop to 10 times means they’re having less sex,” Davis says. “Another woman could be satisfied having sex three times a month.”
*
(BEGIN TEXT OF INFOBOX)
Testosterone for women, in small doses
Since its discovery as the main sex-drive drug in men, testosterone also has been found to improve sex drive in perhaps 60% of women who try it.
Despite this evidence, a testosterone patch from Procter & Gamble that was designed to enhance sex drive in women recently failed to win Food and Drug Administration approval, on the grounds that the researchers hadn’t shown it to be safe. (The product was, however, granted approval in Europe.)
Nonetheless, doctors are prescribing, and women are seeking, off-label testosterone treatments to enhance libido, arousal and ability to orgasm.
The hormone is supplied in a variety of ways: as creams applied to genital areas or skin or as drops taken under the tongue. (The body digests the hormone if it’s taken via pills.)
One tack that’s not recommended: patches available for men. These have testosterone in much higher doses -- perhaps 2.5 times higher -- than needed in women, says Dr. Erika Schwartz, of the Integrative Medicine Consultative Practice in New York City.
Instead, to get treatments at doses appropriate for women, many doctors use compounding pharmacies and labs that mix custom creams with the appropriate amounts of hormone.
Some doctors even recommend small amounts of prescription-only AndroGel, which contains testosterone and can be rubbed into skin.
However, “the safety of this approach long-term is unclear,” says psychiatrist Dr. Taylor Segraves of the Case Western School of Medicine in Cleveland.
-- Mary Beckman
